Parkinson's disease affects between 5 and 7 million people, and is the second largest neurological disease. Parkinson's disease is degenerative and there is currently no cure. Parkinson's disease is caused by a loss of dopamine in the neurons of the human body. To track the progression of the disease, subjects are periodically evaluated by medical professionals using established rating scales. An example rating scale for Parkinson's disease is the Movement Disorder Society unified Parkinson's disease rating scale (MDS-UPDRS). As explained below, the current examination methods for subjects with Parkinson's disease (and other neurological diseases) have several significant limitations.
Currently, examinations of subjects are performed by doctors during office visits. Subjects with Parkinson's disease typically visit a doctor's office once or twice a year. Thus, their condition is only monitored 1 to 2 hours per year. This leaves about 8,758 hours per year when their condition is not being monitored.
Established rating scales (such as the MDS-UPDRS) typically include questionnaires and a series of motor exercises. Currently, a doctor watches a subject performing each of the motor exercises and then determines a rating for the subject's movement based on a series of prescribed guidelines. Many of the prescribed guidelines are subjective and open to the interpretation of the doctor performing the examination. For example, a prescribed guideline may require the doctor to differentiate between a subject walking with minor gait impairment and with substantial gait impairment. In addition, many of the prescribed guidelines require the doctor to evaluate attributes that are difficult to discern with eyeball judgement. For example, a prescribed guideline may require the doctor to differentiate a hand tremor between 1 centimeter and 3 centimeters from a hand tremor between 3 centimeters and 5 centimeters.
Further, Parkinson's disease is a very individual disease. Every subject develops different motor and non-motors symptoms at different rates. The currently examination methods employ fixed rating scales that do not account for the symptom development of individual subjects.